WO2018103137A1

WO2018103137A1 - Method for predicting greenhouse tomato fruit growth

Info

Publication number: WO2018103137A1
Application number: PCT/CN2016/110906
Authority: WO
Inventors: 倪纪恒; 刘勇; 周靖宇; 毛罕平
Original assignee: 江苏大学
Priority date: 2016-12-09
Filing date: 2016-12-20
Publication date: 2018-06-14
Also published as: CN106600048A; CN106600048B

Abstract

Method for predicting greenhouse tomato fruit growth, comprising the following steps: 1, with the leaves of a tomato plant as sources and libraries and the stems and fruits as libraries, converting into source-library relations; with the sources as power sources and the libraries as resistances, converting the tomato plant into a circuit on the basis of the source-library relations; 2, utilizing relevant conditions in a greenhouse and the circuit in step 1 to determine a leaf voltage, a leaf resistance, an inter-node resistance, and a fruit resistance of the greenhouse tomato plant; 3, in combination with the circuit of step 1, calculating the voltage and current at either end of the fruits on the basis of the determined leaf voltage, leaf resistance, inter-node resistance, and fruit resistance by utilizing the Ohm's law to produce the electric power of the fruits, the value of the electric power of the fruits being the amount of assimilated products acquired by the greenhouse tomato fruits in one day; and 4, converting the produced amount of the assimilated products of the fruits into the diameter of the greenhouse tomato fruits. The method expresses in the form of electricity the inter-plant distribution of greenhouse tomato assimilated products, thus further facilitating greenhouse environment regulation and nutrient solution management.

Description

Method for predicting growth of tomato fruit in greenhouse

Technical field

The present technology uses a crop simulation model method to predict the growth of greenhouse tomato fruit, specifically a method for predicting the growth of greenhouse tomato fruit, and belongs to the field of facility cultivation technology.

Background technique

The greenhouse crop growth simulation model is a powerful tool for greenhouse environmental regulation and water and fertilizer management. The dry matter distribution sub-model of greenhouse crops is an important part of the greenhouse crop growth simulation model; the dry matter distribution of greenhouse crops directly determines the yield and quality of crop products. However, since the mechanism of dry matter distribution in greenhouse crops is still unclear, the simulation of dry matter distribution in greenhouse crops has always been a hotspot and a difficult point in research.

At present, the main methods for simulating the dry matter distribution of greenhouse crops are the rate-of-speed growth and source-bank theory. The model based on the rate-increasing growth is practical, and the established model has poor universality. The model based on the source-bank theory is highly mechanistic, but because the parameters required to construct the model are many and difficult to measure, the application of the model is limited.

During the growth of greenhouse crops, the leaves absorb light and carbon dioxide, synthesize organic matter and release oxygen. The organic matter synthesized by the leaves is transported through stems to organs such as fruits. Assimilation products form a gradient difference between organs such as leaves and fruits. This is consistent with the transport of current in Ohm's law (although there are two-way transport phenomena in the transport of assimilation products, the overall assimilation product flow is from the blade to the fruit and other organs). In view of this, the present invention uses a blade as a battery, a stem as a wire, a fruit as an electrical appliance, and an assimilation product flow as a current, and constructs a greenhouse tomato growth model based on Ohm's law, which provides a theoretical basis for improving the level of greenhouse production and environmental regulation in China.

Summary of the invention

The object of the present invention is to provide a method for predicting the growth of greenhouse tomato fruit, to improve the environmental control of the greenhouse and the level of water and fertilizer management, and to improve the yield and quality of the greenhouse crop. The specific technical solutions are as follows:

A method for predicting the growth of greenhouse tomato fruit, comprising the following steps:

Step 1. First, the leaves of the tomato plants are used as the source and the reservoir, and the stems and fruits are used as the reservoirs, which are transformed into the source-sink relationship; then, the source is used as the power source, and the reservoir is the resistance, and the tomato plants are converted into circuits according to the source/library relationship;

Step 2: determining the leaf voltage, leaf resistance, internode resistance and fruit resistance of the greenhouse tomato plant by using the relevant conditions in the greenhouse and the circuit obtained in the step 1;

Step 3: Combine the circuit obtained in step 1, and then calculate the voltage and current at both ends of the fruit according to the determined blade voltage, blade resistance, inter-segment resistance and fruit resistance, and obtain the electric power of the fruit, and the electric power value of the fruit is The amount of assimilation product obtained in a greenhouse tomato fruit within one day;

Step 4. Convert the obtained assimilation product amount of the greenhouse tomato fruit into the diameter of the greenhouse tomato fruit.

The specific process of converting a tomato plant into a circuit is:

When the tomato plant is a plant with m-branched n-fruit branches, m is a natural number ≥1, n=0 or a natural number ≥1, and the circuit of conversion is:

Each leaf branch of the m-leaf branch is transformed into a blade resistance RL connected in series with a blade battery E, a total of m blades and m blade batteries, and m blade resistances are respectively recorded as RL1, RL2, ... RLm The voltages of the m vane batteries are respectively recorded as E1, E2, ... Em;

Each fruit branch is transformed into a fruit resistance Rf, a total of n fruit resistances, n fruit resistances are recorded as Rf1, Rf2 ... Rfn;

The stem of the plant of the m-leaf branch is composed of m+n internodes, and each internode is converted into an inter-segment resistance Rs, and the inter-segment resistance Rs from the root is sequentially recorded as Rs1, Rs2... Rsm+n, then connect the Rs1, Rs2...Rsm+n node resistances in series;

One end of each blade resistor RL is connected in series with one vane battery E, and the other end of each vane resistor RL is connected between different two inter-node resistors Rs, and the other end of each vane battery E is grounded;

One end of each fruit resistance Rf is grounded, and the other end is connected between different two inter-node resistances Rs, so that the other end of each fruit resistance Rf is connected in series with the other end of each blade resistance RL. Inter-resistance Rs;

Therefore, the other end of the total of m blade resistances and the other ends of the total of n fruit resistances are connected between different two inter-node resistances Rs1, Rs2, ..., Rsm+n.

In step 2, the blade voltage satisfies the following formula:

Where E is the blade voltage, P _{max is} the maximum photosynthesis rate of the blade (unit: kgCO ₂ ·ha ^-1 ·h ^-1 ), and ε is the light conversion factor, ie the initial light energy utilization efficiency of the absorbed light (unit: kg CO ₂ · ha ^-1 ·h ^-1 /J·m ^-2 ·s ^-1 ), according to the experimental observation data, the value of ε is 0.40 (unit: kg CO ₂ · ha ^-1 · h ^-1 /J·m ^{- 2} · s ^-1 ), P _max is 37 (unit: kg CO ₂ · ha ^-1 · h ^-1 ); PAR (T) is the photosynthetically active radiation PAR absorbed by the leaf at time T (unit: J·m ^{- 2} · s ^-1), a leaf area (blade unit: m ^2); d is the density of the plants, strains units / m², T is the time in hours.

The method for determining the leaf area of the blade is:

Step a1, determining the maximum leaf length of the blade and the average growth rate of the blade according to the leaf order, the maximum leaf length satisfying the following formula:

The average growth rate of the blades satisfies the following formula:

Where Lmax is the maximum leaf length of the leaf, the maximum leaf length is the maximum length when the leaf grows into mature leaves; V is the average growth rate of the leaves; i is the leaf order, that is, the number of leaves i obtained from the root number, this When the greenhouse tomato grows from vegetative growth to vegetative growth and reproductive growth;

Step a2, determining the cumulative effective accumulated temperature of the blade:

First, according to the following formula, the cumulative effective accumulated temperature of the first true leaf is expanded to the nth day after the expansion of any leaf:

G=∑(Tmean-Tb),

Then, according to the following formula, the cumulative effective accumulated temperature from the rth day to the jth day after the first true leaf is expanded to any leaf unfolding is obtained:

ΔGrj=Gj-Gr,

Where G is the cumulative effective accumulated temperature required for the first true leaf to the nth day after expansion of any leaf; Tmean is the daily average temperature of the day; Tb is the boundary temperature, which is common knowledge; ΔGrj is the first true leaf unfolded until Cumulative effective accumulated temperature from day r to day j after a leaf unfolding; Gr is the cumulative effective accumulated temperature required for the first true leaf to the r-day after any leaf unfolding, and Gj is the first true leaf unfolded to any leaf The cumulative effective accumulated temperature required on the jth day after deployment;

Step a3, determining the leaf length of the blade according to the maximum leaf length of the blade obtained by the steps a1 and a2, the average growth rate of the blade, and the cumulative effective accumulated temperature, which satisfy the following formula:

Where L is the leaf length of the blade, Lmax is the maximum leaf length of the blade, V is the average growth rate of the blade, and ΔGrj is the cumulative effective accumulated temperature from the rth day to the jth day after the blade is deployed;

Step a4, determining the leaf area of the blade according to the leaf length of the blade obtained in the step a3, and satisfying the following formula:

A=K×L ² /10000,

Where A is the leaf area of the blade and L is the leaf length of the blade.

The photosynthetically active radiation PAR absorbed by the blade satisfies the following formula:

PAR=PARo×e ^-kAI ,

Among them, PARO is the photosynthetically active radiation value above the blade, which is common knowledge; k is the extinction coefficient, and the value is 0.8; AI is the leaf area index above the blade, that is, the leaf area above the blade is multiplied by the blade density.

In step 2, the blade resistance satisfies the following formula:

Among them, RL is the blade resistance, Rm(T ₂₅ ) is the maintenance breathing coefficient of tomato at 25 °C, Rm(T ₂₅ ) is 0.015 (kg CH ₂ O·kg ^-1 DM·d ^-1 ), W is leaf stem Heavy (kgDM·ha ^-1 ), T is the daily average temperature (°C).

The dry weight of the leaf satisfies the following formula:

W=A×S _A ,

Where W is the dry weight of the leaves, A is the leaf area of the leaves, and S _A is the specific leaf area, which is 40m ² kg ^-1 .

In step 2, the inter-segment resistance satisfies the following formula:

Where Rs is the inter-segment resistance, C is the inter-blocking resistivity, Ln is the inter-segment length, and Dn is the inter-segment diameter.

The method for determining the length of the internode is:

Step b1: determining an average growth rate between the nodes, the average growth rate of the internodes satisfying the following formula:

Wherein, Vn is the average growth rate between the nodes, and i is the leaf order;

Step b2: Determine the inter-segment length according to the cumulative effective accumulated temperature of the blade obtained in step b1 and the inter-node average growth rate, wherein the inter-segment length satisfies the following formula:

Wherein, Ln is the internode length, Vn is the internode average growth rate, and ΔGrj is the cumulative effective accumulated temperature from the rth day to the jth day after the blade is deployed.

The method for determining the internode diameter is:

Step c1: determining an average growth rate of the internode diameter according to the leaf order, and the average growth rate of the internode diameter satisfies the following formula:

Where Vdn is the average growth rate of the internode diameter and i is the leaf order;

Step c2, determining an internode diameter according to an accumulated effective accumulated temperature of the blade and an average growth rate of the internode diameter, wherein the internode diameter satisfies the following formula:

Where Dn is the internode diameter, Vdn is the average growth rate of the internode diameter, and ΔGrj is the cumulative effective accumulated temperature from the rth day to the jth day after the blade is deployed.

The method for determining the inter-blocking resistivity is:

The inter-sector resistivity is determined according to the inter-segment diameter and the inter-segment length, and the inter-segment resistivity satisfies the following formula:

Where C is the inter-blocking resistivity, Dn is the inter-node diameter, and Ln is the inter-segment length.

The specific derivation process of the fruit electric power is:

Step d1: Conversion of tomato plants: For tomato plants having m-leaf branches and n-fruit branches, tomato leaves start from the roots, and are referred to as leaves 1, leaves 2, leaves m, then leaves 1 and 2 ... leaf m is a battery and a resistor, respectively, the voltage is E1, E2 ... Em, the blade resistance is R1, R2 ... Rm; a total of m+1 Between the nodes, the resistance is called Rs1, Rs2, ... Rsm, Rsm+1; there are n fruit branches, respectively called Rf1, Rf2, ... Rfn;

Step d2, predicting each blade according to the maximum leaf length of the blade, the average growth rate of the blade, the effective accumulated temperature on the nth day after the blade is deployed, the cumulative effective accumulated temperature from the rth day to the jth day after the blade is deployed, and the leaf length of the blade The leaf length, the internode length and the internode diameter of each stem are obtained according to the inter-segment resistance, the internode average growth rate, the internode length, the average growth rate of the internode diameter, and the internode diameter;

Step d3, according to the photosynthetically active radiation PAR absorbed by the blade, the collected photosynthetically effective radiation in the greenhouse The value of photosynthetically active radiation received by each blade is calculated by the injection value, and the voltage of the blade is calculated by Equation 1. Then, according to the maximum leaf length of the blade, the average growth rate of the blade, the effective accumulated temperature on the nth day after the blade is unfolded, and the blade is expanded from the first The cumulative effective accumulated temperature from the r-day to the j-th day, the leaf length of the leaves, the leaf area of the leaves, and the leaf resistance calculate the dry weight of each leaf, ie the resistance of each blade; the simulated internode length and internode diameter of the stem The inter-segment resistivity obtained in step 2 obtains the inter-block resistance;

Step d4, using the superposition theorem to divide the circuit into m sub-circuits, respectively calculate the currents on the fruit resistances of the m sub-circuits and sum them, that is, obtain the actual current on the fruit resistance, and use the Thevenin theorem on the current in each sub-circuit Solve; find the current of Rf on m sub-circuits, and then add to get the total current, then the total power on the fruit branch is multiplied by the square of the total current to get the total electric power of the fruit in one day, that is, one day The amount of assimilation product.

In step 4, the diameter of the greenhouse tomato fruit satisfies the following formula:

Where P is the electric power P of the fruit.

Beneficial effects:

Compared with the traditional fruit prediction model, this model has the following advantages:

First, the current greenhouse tomato growth model mostly uses the source-sink theory to simulate the growth of greenhouse tomato fruit. In the source-sink theory, the strength of the reservoir, especially the arsenic of the vegetative organs, is difficult to quantify. Based on the theory of pressure-impedance, the present invention proposes a prediction model for greenhouse tomato fruit growth based on Ohm's law, which overcomes the insufficiency of vegetative organ pooling, and regulates environmental management and nutrient solution in greenhouse tomato production in China. Agronomic measures provide a theoretical basis.

Second, the traditional greenhouse tomato growth model takes crop production as the core, while the preparation of greenhouse environmental regulation and nutrient solution management is mostly based on electricity, which is caused by different ways of thinking. The growth model brings a lot of inconvenience in application promotion. In the present invention, the distribution of greenhouse tomato assimilation products in plants is embodied in the form of electricity, which is more conducive to the preparation of greenhouse environment regulation and nutrient solution management.

Third, the traditional greenhouse tomato fruit prediction model is based on the growth process of tomato. The invention patent is based on the intersection of agronomy and electricity. Very innovative.

DRAWINGS

1 is a schematic view of step 1 of the first embodiment of the present invention, wherein FIG. A is a schematic diagram of a greenhouse tomato plant with 9 leaves and 1 leaf, and FIG. B is a source-sink relationship diagram of a greenhouse tomato plant of FIG. A, and FIG. Converted from Figure B The circuit diagram is formed; RL1 to RL9 are the first to ninth blade resistances; Rs1 to Rs10 are the first to tenth inter-segment resistances; E1 to E9 are the first to ninth blade batteries; and Rf1 is the fruit resistance of the first fruit.

2 is a schematic view showing a double-bar pruned tomato plant in Example 1;

In Fig. 3, Fig. A is an equivalent circuit diagram of a double-bar pruned tomato plant in the first embodiment, Fig. B is a simplified circuit diagram of Fig. A, and Fig. C is a current flow diagram;

In Fig. 4, Fig. A is a schematic view of a tomato plant in Example 2, and Fig. B is an equivalent circuit diagram of Fig. A.

detailed description

The present invention is further described below in conjunction with the accompanying drawings and embodiments:

Example 1:

In the present invention, the number of tomato fruits on the fruit branches may be more than one, and when the number of fruits is more than one, it is assumed that all the fruits have the same diameter.

Step 1. Converting the tomato plants; firstly, converting the tomato plants according to the source/library relationship, that is, the leaves are the source and the reservoir (the leaves in the greenhouse tomato production are used for photosynthesis production, and the partial photosynthetic products are used to maintain the leaf consumption, ie The leaves maintain the breathing), the stems and fruits are the reservoirs, which are transformed into source-pool relationships. Then, using the source as the power source and the library as the resistor, the tomato plants are converted into circuits. In the following, the greenhouse tomato plants with 9 leaves and 1 fruit (9 leaf branches and 1 fruit branch) are taken as an example to illustrate the transformation method. First, the greenhouse tomato plants with 9 leaves and 1 fruit are selected, and then the transformation is carried out according to the source-sink relationship. Source/library, stem and fruit are libraries. Then, the source is the battery, and the library is used as a resistor to convert the greenhouse tomato plants. After conversion, the leaves on the greenhouse tomato plants were transformed into a resistance plus a battery, and the resistance was sequentially referred to as RL1, RL2--RL9 from the root, and the voltages were sequentially referred to as E1, E2--E9. 9 leaves 1 The stem of the greenhouse tomato consists of 10 internodes, each of which is a resistor, which is called Rs1--Rs10 from the root. One fruit branch is a resistor called Rf1. In order to clearly explain the conversion process, the present invention selects a greenhouse tomato with 9 leaves and 1 fruit, and other forms of tomato can be converted.

That is to say: when the tomato plant is a plant with m-branched n-fruit branches (m is a natural number ≥1, n=0 or a natural number ≥1), the circuit of conversion is:

The stem of the plant of the m-leaf n-fruit branch consists of m+n internodes, transforming each internode into an inter-segment resistance Rs, The inter-segment resistance Rs from the root is sequentially referred to as Rs1, Rs2, ..., Rsm+n, and then the Rs1, Rs2, ..., Rsm+n node resistances are sequentially connected in series;

Therefore, the other end of the total of m blade resistances, the other end of the total of n fruit resistances is connected between different two inter-node resistors Rs1, Rs2, ... Rsm + n;

As described above, a schematic view as shown in Fig. 1 is formed.

2.1, the blade voltage satisfies the formula (1):

Where E is the blade voltage, P _{max is} the maximum photosynthesis rate of the blade (unit: kg CO ₂ ·ha ^-1 ·h ^-1 ), and ε is the light conversion factor, ie the initial light energy utilization efficiency of the absorbed light (unit: kg CO ₂ ·ha ^-1 ·h ^-1 /J·m ^-2 ·s ^-1 ), according to experimental observation data, ε is 0.40 (unit: kg CO ₂ ·ha ^-1 ·h ^-1 /J·m ^-2 · s ^-1), P _max value of 37 _{^{(unit: kg CO 2 · ha -1 ·}} h -1); PAR (T) for the time T PAR blade absorbed photosynthetic active radiation (unit: J · m ^-2 · s ^-1 ), A is the leaf area of the leaf (unit: m ² ); d is the plant density, the unit is plant / square meter, T is the time, the unit is hour.

The method for determining the leaf area of the blade is:

Step a1: determining a maximum leaf length of the blade and an average growth rate of the blade according to the leaf order, the maximum leaf length satisfying the formula (2), and the average growth rate of the blade satisfies the formula (3):

G=∑(Tmean-Tb) (4),

ΔGrj=Gj-Gr (5),

The value of the limit temperature Tb of each growth period of tomato is shown in Table 1:

Table 1 The value of the limit temperature Tb of each growth period of tomato

Step a3, determining the leaf length of the blade according to the maximum leaf length of the blade obtained by the steps a1 and a2, the average growth rate of the blade, and the cumulative effective accumulated temperature, which satisfies the formula (6):

Step a4, determining the leaf area of the blade according to the leaf length of the blade obtained in the step a3, and satisfying the formula (7):

A=K×L ² /10000 (7),

Where A is the leaf area of the blade; K is the proportional coefficient, dimensionless; L is the leaf length of the blade.

The photosynthetically active radiation PAR absorbed by the blade satisfies the formula (8):

PAR=PARo×e ^-kAI (8),

2.2, calculation of blade resistance RL:

The blade resistance satisfies equation (9):

Among them, RL is the blade resistance, Rm(T ₂₅ ) is the maintenance breathing coefficient of tomato at 25 °C, Rm(T ₂₅ ) is 0.015 (kg CH ₂ O·kg ^-1 DM·d ^-1 ), W is leaf stem Heavy (kg DM·ha ^-1 ), T is the daily average temperature (°C).

The dry weight of the leaf satisfies the formula (10):

W=A×S _A (10),

2.3, calculation of the inter-node resistance Rs:

The inter-segment resistance satisfies the formula (11):

The method for determining the length of the internode is:

Step b1: determining an average growth rate between the nodes, wherein the average internode growth rate satisfies the formula (12):

Step b2, determining the inter-segment length according to the cumulative effective accumulated temperature of the blade obtained in step b1 and the inter-node average growth rate, wherein the inter-segment length satisfies the formula (13):

Where Ln is the internode length, Vn is the average internode growth rate, and ΔGrj is the rth to jth after the blade is unfolded The cumulative effective accumulated temperature of the day.

The method for determining the internode diameter is:

Step c1: determining an average growth rate of the internode diameter according to the leaf order, and the average growth rate of the internode diameter satisfies the formula (14):

Step c2: determining an internode diameter according to an accumulated effective accumulated temperature of the blade and an average growth rate of the internode diameter, wherein the internode diameter satisfies the formula (15):

2.4, the determination of the internode resistivity C and the fruit resistance Rf:

The inter-blocking resistivity C and the fruit resistance Rf were determined by experiments.

2.4.1 Test design

The test was carried out in a greenhouse, and the test greenhouse crop was tomato, which was cultivated in a cultivation tank, and the cultivation substrate was perlite. Irrigation with Hoagland nutrient solution. Tomatoes use double-rod pruning, which are A and B respectively. Three representative plants were selected for measurement. details as follows:

Four leaves are left on the A rod, one fruit branch is left at the second node of the B pole, and two fruits are left on the fruit branch; the B rod leaves no leaves, as shown in Fig. 2.

2.4.2 Determination items and methods

On the third day after the treatment, the internode length and internode diameter in the A and B rods were measured daily; the leaf length and the fruit diameter. Environmental factors: The required greenhouse and radiation data are automatically collected by the greenhouse control system.

2.4.3 Data Analysis

(a) First calculate the single leaf area A of the greenhouse tomato using the measured blade length on the double rod of the tomato, using equation (2): A = K × L ² / 10000, and then use the formula (11): W = A × S _A , calculate the dry weight W of the leaf, using the formula (1):

Each blade voltage E is calculated, and each blade resistance RL is calculated by the formula (10): RL = Rm (T ₂₅ ) × W × 2 ^(T-25)/10 .

(b) Convert each process in the test and convert each process into a circuit diagram mode.

(c) Calculate the inter-node dry weight, leaf dry weight and dry weight of the fruit based on the measured internode length, leaf length and fruit diameter.

Inter-node dry weight = inter-section length × 0.11 (16),

The dry weight of the fruit = 0.025 × the cube of the fruit diameter (17),

Internode length and fruit diameter can be obtained by direct measurement.

(d) According to formulas (7), (16), (17), the stem, leaf and dried fruit weight are subtracted from the stem, leaf and dried fruit weight of the previous day, and the daily growth of stem, leaf and fruit can be obtained. The dry weight between the nodes is the dry weight of the stem.

(e) Using the electric power of the stem, leaf, and fruit on the stem and leaf fruit, the electric resistance between the fruit resistance Rf and the stems on the stem is solved.

2.4.4 Specific calculation process

The measured leaf lengths of greenhouse tomatoes were 25, 29, 35, and 33 cm, respectively. The photosynthetically active radiation values and temperature values above the leaves are shown in Table 2. Using the formula (1), the daily assimilation product amount (ie, voltage) was calculated. The photosynthetic product amounts of the leaves of tomato in one day were 7.31, 7.43, 8.01, 5.19 Kg CO ₂ ha ^-1 d ^{-1 , respectively} . Using the formula (9), the leaf-retaining spirometry was calculated to be 0.010, 0.0122, 0.018, 0.016 Kg CO ₂ ha ^-1 d ^-1 (ie, blade resistance). The voltages of the first, second, third and fourth leaves were 7.31, 7.43, 8.01, 5.19, respectively, and the resistances were 0.010, 0.0122, 0.018, and 0.016, respectively. The daily growth of stem, leaf and fruit were 6.25, 7.25 and 10.75Kg, respectively. DM ha ^-1, the stems, leaves electric power, 6.25,7.25 and 10.75 for the fruit. The growth of the four blades was 2.01, 2.3, 1.94 and 1 (measured values), respectively, and the electric power of the four blades was 2.01, 2.3, 1.94 and 1.

Table 2 Photosynthetically active radiation and temperature of greenhouse tomato

According to the equivalent circuit diagram shown in FIG. 3 in FIG. 3 and the simplified circuit diagram obtained in FIG.

R'=(Rs5+Rf)//(Rs6+Rs7+Rs8)+Rs1;

For the circuit diagram shown in FIG. 3, U1, U2, U3, U4, RL1, RL2, RL3, RL4, P1, P2, P3, P4, Pf, Ps are known; solution, Rs1, Rs2, Rs3, Rs4, Rs5, Rs6, Rs7, Rs8, and Rf; wherein RL1 to RL4 are blade resistances of four blades, respectively, P1, P2, P3, and P4 are electric powers of four blades, respectively, Pf is fruit electric power, and Ps is inter-segment electric power.

solution:

Substituting the values of known U1, U2, U3, U4, RL1, RL2, RL3, RL4, P1, P2, P3, and P4 into the above formula, Rs2, Rs3, and Rs4 are obtained, respectively, being 0.092, 0.052, and 0.096. . Using the measured internode diameters and internode lengths between the 2nd, 3rd, and 4th sections, the resistivity between the 2nd, 3rd, and 4th sections is calculated by the following formula (18).

Then take the average to get the average resistivity between the nodes. According to the obtained average resistivity and the internode length and the internode diameter of the

internodes

1, 5, 6, 7, and 8, the internode resistance of the

internodes

1, 5, 6, 7, and 8 is calculated according to the formula (11). . Then, the value of R' is calculated, and the fruit resistance Rf is finally calculated.

Table 3 shows the greenhouse tomato electrical parameters calculated based on environmental factors:

Table 3: Greenhouse tomato electrical parameters calculated based on environmental factors

Step 3. Using the determined blade voltage, blade resistance, internode resistance, and fruit resistance, the voltage and current at both ends of the fruit are calculated using Ohm's law to obtain the fruit power.

For tomato plants with m-leaf and n-fruit branches, according to the circuit diagram after conversion. Firstly, the blade voltage and the blade resistance were calculated by temperature and radiation, and then the length and diameter of each section were calculated by the effective accumulated temperature. The inter-node resistance and the fruit resistance were calculated by the inter-block resistivity obtained in step 2. Then, the current of each fruit branch is obtained, and the electric power of each fruit branch current is calculated. The electric power of each fruit current is the amount of daily assimilation product obtained by the fruit branch. Further, the daily growth of the fresh weight of the fruit is derived, and finally the diameter of the fruit and the daily increase of the fresh weight are obtained.

Among them, the fresh weight of the fruit = 0.5 × the cube of the diameter of the fruit.

details as follows:

Transform the tomato plants. For tomato plants with m-leaf and n-fruit branches, tomato leaves start from the root and are called leaf 1 , leaf 2 ... leaf m in order, then leaf 1 , leaf 2 ... leaf m respectively For one battery and resistor, the voltages are E1, E2, ... Em, and the blade resistances are R1, R2, ... Rm, respectively. There are a total of m+1 internodes, and their resistances are called Rs1, Rs2, ... Rsm, Rsm+1, respectively. There are n fruit branches, which are called Rf1, Rf2, ... Rfn.

The leaf length of each leaf is predicted by the formulas (2) to (6), and the internode length and the internode diameter of each stem are obtained by the formulas (11) to (15).

The photosynthetically active radiation value received by each blade is calculated by using the formula (8) to calculate the photosynthetically active radiation value per hour of the collected greenhouse, and the voltage of the blade is calculated by Equation 1. Then, the dry weight of each blade, that is, the resistance of each blade, is calculated using equations (2) to (7) and (9). The inter-node resistance was obtained by the formula (11) by the inter-segment length and the inter-segment diameter of the simulated stem and the inter-block resistivity obtained in the step 2.

The superposition theorem is used to divide the circuit into m sub-circuits, and the currents on the fruit resistances of the m sub-circuits are respectively obtained and summed to obtain the actual current on the fruit resistance. The current on the fruit branches in each sub-circuit is solved by the Thevenin theorem. Find the current of Rf on m sub-circuits, and then add them to get the total current. Then the total power on the fruit branches is multiplied by the square of the total current to obtain the total electric power of the fruit in one day, that is, the assimilation obtained in one day. The amount of product.

Step 4. The electric power P of the fruit obtained by the step 3, that is, the amount of assimilation product obtained in one day of the greenhouse tomato fruit. The diameter of the fruit is then determined based on the amount of assimilated product obtained from the fruit. details as follows:

Fresh fruit weight = 0.5 × fruit diameter cube,

Where P is the electric power P of the fruit.

As a result, the diameter of the fruit on the first day was 1.5 cm.

Example 2:

Step 3 in Embodiment 1 is exemplified, as shown in FIG. 4:

Transform the tomato plants. For the sake of simplicity, the greenhouse tomato plants with 3 leaves and 1 fruit (3 leaf branches and 1 fruit branch) were selected, and the tomato leaves were leaf 1, leaf 2 and leaf 3 from the root. Then, leaf 1, leaf 2, and leaf 3 are respectively a battery and a resistor, and the voltages thereof are E1, E2, and E3, respectively, and the blade resistances are RL1, RL2, and RL3, respectively. There are 4 internodes, the resistance is called Rs1, Rs2, Rs3 and Rs4, respectively, and the fruit branch is a resistor called Rf.

According to the model (1), (3) and (8), the photosynthetically active radiation and temperature are still based on the environmental data in Table 2, combined with the data in Table 4, according to the model predictions (25, 29, 35 cm). Leaf voltage, blade resistance, internode resistance, and fruit resistance Rf were obtained.

Table 4 Electrical parameters of greenhouse tomato plants

Claims

A method for predicting growth of a tomato fruit in a greenhouse, comprising the steps of:

Step 1. First, the leaves of the tomato plants are used as the source and the reservoir, and the stems and fruits are used as the reservoirs, which are transformed into the source-sink relationship; then, the source is used as the power source, and the reservoir is the resistance, and the tomato plants are converted into circuits according to the source/library relationship;

Step 2: determining the leaf voltage, leaf resistance, internode resistance and fruit resistance of the greenhouse tomato plant by using the relevant conditions in the greenhouse and the circuit obtained in the step 1;

Step 3: Combine the circuit obtained in step 1, and then calculate the voltage and current at both ends of the fruit according to the determined blade voltage, blade resistance, inter-segment resistance and fruit resistance, and obtain the electric power of the fruit, and the electric power value of the fruit is The amount of assimilation product obtained in a greenhouse tomato fruit within one day;

Step 4. Convert the obtained assimilation product amount of the greenhouse tomato fruit into the diameter of the greenhouse tomato fruit.
The method for predicting the growth of a greenhouse tomato fruit according to claim 1, wherein the specific process of converting the tomato plant into a circuit according to a source/library relationship is:

When the tomato plant is a plant with m-branched n-fruit branches, m is a natural number ≥1, n=0 or a natural number ≥1, and the circuit of conversion is:

Each leaf branch of the m-leaf branch is transformed into a blade resistance RL connected in series with a blade battery E, a total of m blades and m blade cells, and m blade resistances are respectively recorded as RL1, RL2, ... RLm, m blades The voltage of the battery is recorded as E1, E2 ... Em;

Each fruit branch is transformed into a fruit resistance Rf, a total of n fruit resistances, n fruit resistances are recorded as Rf1, Rf2 ... Rfn;

The stem of the plant of the m-leaf branch is composed of m+n internodes, and each internode is converted into an inter-segment resistance Rs, and the inter-segment resistance Rs from the root is sequentially referred to as Rs1, Rs2, ... Rsm+n, Then, the Rs1, Rs2, ... Rsm + n node resistances are sequentially connected in series;

One end of each blade resistor RL is connected in series with one vane battery E, and the other end of each vane resistor RL is connected between different two inter-node resistors Rs, and the other end of each vane battery E is grounded;

One end of each fruit resistance Rf is grounded, and the other end is connected between different two inter-node resistances Rs, so that the other end of each fruit resistance Rf is connected in series with the other end of each blade resistance RL. Inter-resistance Rs;

Therefore, the other end of the total of m blade resistances and the other ends of the total of n fruit resistances are connected between different two inter-node resistances Rs1, Rs2, ..., Rsm+n.
A method for predicting growth of a greenhouse tomato fruit according to claim 1, wherein in the step 2, the blade voltage satisfies the following formula:

Where E is the blade voltage, P max is the maximum photosynthesis rate of the leaf; ε is the light conversion factor; PAR(T) is the photosynthetically active radiation PAR absorbed by the leaf at T time; A is the leaf area of the leaf; d is the plant density; T is the moment.
A method for predicting growth of a greenhouse tomato fruit according to claim 3, wherein the method for determining the leaf area of said leaf is:

Step a1, determining the maximum leaf length of the blade and the average growth rate of the blade according to the leaf order, the maximum leaf length satisfying the following formula:

The average growth rate of the blades satisfies the following formula:

Where Lmax is the maximum leaf length of the leaves; V is the average growth rate of the leaves; i is the leaf order;

Step a2, determining the cumulative effective accumulated temperature of the blade:

First, according to the following formula, the cumulative effective accumulated temperature of the first true leaf is expanded to the nth day after the expansion of any leaf:

G=∑(Tmean-Tb),

Then, according to the following formula, the cumulative effective accumulated temperature from the rth day to the jth day after the first true leaf is expanded to any leaf unfolding is obtained:

ΔGrj=Gj-Gr,

Where G is the cumulative effective accumulated temperature required for the first true leaf to the nth day after expansion of any leaf; Tmean is the daily average temperature of the day; Tb is the boundary temperature, which is common knowledge; ΔGrj is the first true leaf unfolded until Cumulative effective accumulated temperature from day r to day j after a leaf unfolding; Gr is the cumulative effective accumulated temperature required for the first true leaf to the r-day after any leaf unfolding, and Gj is the first true leaf unfolded to any leaf The cumulative effective accumulated temperature required on the jth day after deployment;

Step a3, determining the leaf length of the blade according to the maximum leaf length of the blade obtained by the steps a1 and a2, the average growth rate of the blade, and the cumulative effective accumulated temperature, which satisfy the following formula:

Where L is the leaf length of the blade;

Step a4, determining the leaf area of the blade according to the leaf length of the blade obtained in the step a3, and satisfying the following formula:

A=K×L 2 /10000,

Where K is the proportionality factor.
A method for predicting growth of a greenhouse tomato fruit according to claim 3, wherein the photosynthetically active radiation PAR absorbed by said leaves satisfies the following formula:

PAR=PARo×e -kAI ,

Among them, PAro is the photosynthetically active radiation value above the blade; k is the extinction coefficient; AI is the leaf area index above the blade.
A method for predicting growth of a greenhouse tomato fruit according to claim 1, wherein in the step 2, the blade resistance satisfies the following formula:

Where RL is the blade resistance, Rm(T 25 ) is the sustained breathing coefficient of tomato at 25 ° C; W is the dry weight of the leaf; T is the average daily temperature;

The dry weight of the leaf satisfies the following formula:

W=A×S A ,

Where A is the leaf area of the blade; S A is the specific leaf area.
A method for predicting growth of a greenhouse tomato fruit according to claim 1, wherein in step 2, the inter-segment resistance satisfies the following formula:

Where Rs is the inter-segment resistance; C is the inter-segment resistivity; Ln is the inter-segment length; and Dn is the inter-segment diameter.
A method for predicting growth of a greenhouse tomato fruit according to claim 7, wherein the method for determining the internode length is:

Step b1: determining an average growth rate between the nodes, the average growth rate of the internodes satisfying the following formula:

Wherein, Vn is the average growth rate between the nodes; i is the leaf order;

Step b2: Determine the inter-segment length according to the cumulative effective accumulated temperature of the blade obtained in step b1 and the inter-node average growth rate, wherein the inter-segment length satisfies the following formula:

Wherein, Ln is the internode length; Vn is the internode average growth rate; ΔGrj is the cumulative effective accumulated temperature from the rth day to the jth day after the blade is deployed;

The method for determining the internode diameter is:

Step c1: determining an average growth rate of the internode diameter according to the leaf order, and the average growth rate of the internode diameter satisfies the following formula:

Where Vdn is the average growth rate of the internode diameter and i is the leaf order;

Step c2, determining an internode diameter according to an accumulated effective accumulated temperature of the blade and an average growth rate of the internode diameter, wherein the internode diameter satisfies the following formula:

Wherein Dn is the internode diameter; Vdn is the average growth rate of the internode diameter; ΔGrj is the cumulative effective accumulated temperature from the rth day to the jth day after the blade is deployed;

The method for determining the inter-blocking resistivity is:

The inter-sector resistivity is determined according to the inter-segment diameter and the inter-segment length, and the inter-segment resistivity satisfies the following formula:

Where C is the inter-blocking resistivity; Dn is the inter-segment diameter; Ln is the inter-segment length.
The method for predicting the growth of a greenhouse tomato fruit according to claim 1, wherein in the step 3, the specific derivation process of the fruit electric power is:

Step d1: Conversion of tomato plants: For tomato plants having m-leaf branches and n-fruit branches, tomato leaves start from the roots, and are referred to as leaves 1, leaves 2, ... leaves m, then leaves 1, leaves 2, ... leaves m They are respectively a battery and a resistor, and their voltages are E1, E2, ... Em, respectively, and the blade resistances are R1, R2, ... Rm; there are m+1 internodes, and their resistances are called Rs1, Rs2, ... Rsm, respectively. Rsm+1; there are n fruit branches, called Rf1 Rf2...Rfn;

Step d2, predicting each blade according to the maximum leaf length of the blade, the average growth rate of the blade, the effective accumulated temperature on the nth day after the blade is deployed, the cumulative effective accumulated temperature from the rth day to the jth day after the blade is deployed, and the leaf length of the blade The leaf length, the internode length and the internode diameter of each stem are obtained according to the inter-segment resistance, the internode average growth rate, the internode length, the average growth rate of the internode diameter, and the internode diameter;

Step d3, calculating the photosynthetically active radiation value received by each blade according to the photosynthetically active radiation PAR absorbed in the greenhouse according to the photosynthetically active radiation PAR absorbed by the blade, calculating the voltage of the blade by using Equation 1; and then according to the maximum leaf length of the blade , the average growth rate of the leaves, the effective accumulated temperature on the nth day after the blade is unfolded, the cumulative effective accumulated temperature from the rth day to the jth day after the blade is unfolded, the leaf length of the leaves, the leaf area of the leaves, and the leaf resistance are calculated. Weight, that is, the resistance of each blade; the inter-segment resistance is obtained by the inter-segment length and the inter-segment diameter of the simulated stem and the inter-block resistivity obtained in step 2;

Step d4, using the superposition theorem to divide the circuit into m sub-circuits, respectively calculate the currents on the fruit resistances of the m sub-circuits and sum them, that is, obtain the actual current on the fruit resistance, and use the Thevenin theorem on the current in each sub-circuit Solve; find the current of Rf on m sub-circuits, and then add to get the total current, then the total power on the fruit branch is multiplied by the square of the total current to get the total electric power of the fruit in one day, that is, one day The amount of assimilation product.
The method for predicting growth of a greenhouse tomato fruit according to claim 1, wherein in step 4, the diameter of the greenhouse tomato fruit satisfies the following formula:

Where P is the electric power P of the fruit.